Socketing machine



April 9, 1968 .0. H. LANDRETH SOCKET ING MACHINE 2 Sheets-Sheet 1 FiledMarch 23, 1966 mm W i T1 F.\ k V T & {n Q Q \M Q R Lw\ Q April 1968 o.H. LANDRETH I 3,376,590

SOCKETING MACHINE Filed March 23, 1966 2 Sheets-Sheet 2 0/ w //e Zane ref5 INVENTOR.

ATTORNEY United States Patent 3,376,590 SOCKETING MACHINE Orville H.Landreth, 7902 Glen Prairie, Houston, Tex. 77017 Filed Mar. 23, 1966,Ser. No. 536,740 8 Claims. (Cl. 10-15) ABSTRAQT OF THE DISCLOSUREApparatus for forming socketed rivets and the like including a plain,cylindrical punch and a collet chuck received thereabout, the punch andcollet having engaging wedging surfaces whereby when these parts areadvanced to push the formed rivet out of the machine, the punch will besecurely gripped by the collet so that the work piece can be disengagedfrom the punch as by retracting the collet and the gripped punch intothe machine.

This invention relates to socketing machines for use, for instance, inthe making of semi-tubular rivets.

Machines now on the market for manufacturing semitubular rivets utilizeappropriate die and header combinations for forming the head, shank, andsocket. In the latter operation, the partially-formed blank isintroduced into the axial bore of a die and then, with the head properlybacked up, an extruding punch or knockout pin with a suitably reducedextremity is driven into the end of the blank causing cold flow of theblank metal to form the socket by extrusion. The socketing punch andblank are then driven forwardly to permit a stripper to be insertedbetween the rivet head and the die, whereupon the socketing punch isforcibly retracted to separate the same from the formed blank. Thisretracting and stripping operation necessitates the provision on thepunch of a radial shoulder which may be engaged by the pull-backmechanism. Such special configuration of the punch materially increasesthe cost of this part. Furthermore, in order to remove the punch, as isfrequently necessary for inspection and/or replacement, it is necessaryfirst to withdraw the extruding dies and to further disassemble themachine. This requires many hours of costly labor and down time.

Accordingly, an object of the present invention is to provide asocketing machine having a simple cylindrical socketing punch and meansfor gripping the punch in stripping the workpiece therefrom.

Another object is to provide a socketing machine, as for makingextruded, semi-tubular rivets, in which the socketing punch can beeasily expelled from the machine for inspection and/or replacementwithout substantial disassembly of the machine.

These objects and others hereafter appearing are attained in myinvention herein disclosed which, in general, consists in the provisionof a simple cylindrical socketing punch in combination with a colletchuck received about the punch in such a way that during expression ofthe formed workpiece blank from the machine, the extruding punch issecurely gripped so that, upon retraction of the collet chuck, with astripper inserted between the rivet head and the die, the punch andformed blank will be separated.

In the accompanying drawings which illustrate the invention,

FIG. 1 is a longitudinal central section through a portion of a machinefor manufacturing semi-tubular rivets;

FIG. 2 is a view of parts of the structure in FIG. 1 in differentoperative position;

FIGS. 3, 4, and 5 are views of the parts in FIG. 2 in other operativerelationships; and

FIG. 6 is a disassembled view of the collet chuck device for grippingthe extruding punch.

3,3755% Patented Apr. 9, 1968 FIG. 1 shows a bed portion 8 of arivet-making machine body having a longitudinal chamber 9 therethrough.At the left end of chamber 9 there is received a die case 10 normallysecured in position by a pin 11 and itself receiving front and rear dieinserts 12 and 13. At the rear of bed chamber 9 there is provided guidestructure 14 and 15 for a plunger 16 which is actuated by suitable meansnot shown. Projecting longitudinally from plunger 16 is an intermediatepin 17, in effect forming part of the plunger means and with its leftend slidably received in a bushing 18 within a collet chuck device,generally designated 19'. The left end of pin 17 abuts the socketing orknockout pin 20 which is generally cylindrical, except for the left-handend 21 which is reduced for socketing the end of a workpiece blank 22,as will be explained.

The portion of the rivet-making apparatus disclosed in FIGS. 1-5 isdesigned for the purpose of performing the last or socketing operationupon the workpiece blank. For this purpose, -a back-up head 25 isprovided with a backup insert 26 having a concave face for closelyfitting against the previously formed head 27 of the rivet to secure theblank in position.

The collet-chuck device 19, as better shown in FIG. 6, includes an outersleeve portion 29 having an intermediate annular collar 30 and a noseportion 32 at its left-hand end with inwardly tapered wall 32a. Slidablyreceived within outer sleeve 29' is the inner sleeve 33 which isgenerally tubular and cylindrical except for longitudinal cuts 34 in theleft portion thereof and an externally tapered nose portion 35 at theleft end. Tapered nose 35 is complementary to internal taper 32a at theend of the outer sleeve 29. Internally of the inner sleeve approximatelyat the beginning of the tapered nose thereof, there is provided aninternal shoulder 36 for a purpose to be described. In the assembly,collar 30 is urged rightwardly against an internal shoulder 31 inchamber 9 by means of a heavy coiled spring 37. A somewhat lightercoiled spring 38 is compressed between the right-hand side of collar 30and a spring seat collar 39 on plunger 16. FIG. 3 shows a strippermember 40 interposed between the head 27 of the expressed rivet and face41 of the die structure to permit separation of the formed rivet andsocketing punch 20.

In operation, parts 29 and 33 of the collet chuck will be loosely nestedso that punch 20 may slide freely therethrough. With the back-up head 25in the position of FIG. 1 abutting a rivet head in the die, plunger 16and intermediate pin 17 will be driven leftwardly to cause socketingpunch 20 to pierce the right-hand end of the rivet blank causingextrusion of the rivet metal and formation of the socket in the shankend, as shown. Plunger 16 then continues its leftward movement, firstcompressing coiled spring 38 and ultimately causing the left-hand end ofintermediate pin 17 to seat against internal shoulder 36 in inner colletmember 33, as shown in FIG. 2. Since pin 17 is slightly longer than thelinear distance between shoulder 36 and the right-hand ends of sleeves29 and 33, pin 17 will remain projected slightly beyond the right end ofthe collet chuck. Thus, continued leftward pressure exerted by theplunger will be applied to inner collet sleeve 29 tending to drive thesame leftwardly with respect to outer collet sleeve 33, sufficientclearance being provided between nose 35 and rear die insert 13 topermit this. The complementary wedging noses of the collet parts willcause inner nose 35 to firmly grip the right-hand end of socketing punch20. The entire collet chuck device may be moved a slight additionaldistance leftwardly to permit stripper block 40 to be inserted betweenrivet head 27 and die means face 41. At the same time, collar 30 willmove leftwardly from annular stop shoulder 31 compressing heavy spring37. Consequently, upon retraction of plunger 16, heavy spring 37 willexpand to retract the collet chuck device rightwardly, carrying with itsocketing punch 20 so as to separate the punch from the formed rivet.Collar 30 will again seat upon stop shoulder 31 (FIG. 4) and the rivetcan drop into a collecting receptacle. Plunger 16 will be fullyretracted to the position of FIG. 1 for the insertion of anotherpartially-formed blank into die means 10, 12, 13.

An important advantage of the novel cylindrical socketing pin 20 is thatit can be readily ejected from the machine without the necessity ofdisassembling either the die or collet chuck means. For instance, theportion of chamber 9 between collar 31 and plunger collar 39 may becharged with compressed air which will be directed past suitableclearance provided in the surface of intermediate pin 17, as by a smallflat thereon, to the rear end of punch 20. With the head 25 and othermachine parts cleared from the die means face, the socketing punch willbe forced leftwardly out of the machine, as indicated in FIG. 5. Thisremoval operation can be performed in ten or fifteen minutes at a savingof at least five or six dollars in production time. Furthermore, verymaterial saving can be made in the cost of production of the socketingpunch due to the decreased number of operations neces sary because ofelimination of the external shoulder heretofore necessary in holding thepunch during the stripping operation.

The form of rivet-making machine as shown herein is, in general,well-known, and its general features may be modified in various respectsas will occur to those skilled in the art. The exclusive within thescope of the appended claims is contemplated.

I claim:

1. Apparatus for making socketed articles comprising a body having achamber, die means in said chamber having an opening therein forreceiving a workpiece blank, a socketing punch movably carried in saidchamber, plunger means aligned with said punch in said chamber andmovable in one direction to a first position for causing blank socketingmovement of said punch and to a second position for ejecting thesocketed blank from said die means, collet chuck means in said chamberabout said punch, stop means in said chamber for opposing movement ofsaid chuck means in said direction, said chuck means having a shoulderengageable by said plunger means in said second position thereof forcausing said chuck use of all modifications as come 4. means to gripsaid punch, and means for stripping the socket blank from said punch.

2. Apparatus as described in claim 1 in which said stop means comprisesa spring and said stripping means includes said spring and means forpreventing retraction of said blank upon retraction of said plungermeans and result-ant shifting of said chuck means by said spring.

3. Apparatus as described in claim 2 in which the body of said punch isuniformly cylindrical and shaped to pass through said chuck and diemeans when said chuck means is relaxed.

4. Apparatus as described in claim 3 in which said chuck means comprisesan inner sleeve with a longitudinally split, exteriorly tapered noseportion and an outer sleeve with a complementary internally tapered noseportion, said portions being capable of relative axial shifting to causesaid inner nose portion to grip the punch therein.

5. Apparatus as described in claim 4 further including a collarprojecting radially from said outer sleeve, said spring being compressedbetween said die means and said collar.

6. Apparatus as described in claim 5 in which said shoulder engageable'by said plunger means is formed by an internal shoulder within saidinner sleeve for applying the force of said plunger means through saidcomplementary tapered noses to said spring.

7. Apparatus as described in claim 6 in which said plunger meansincludes a main plunger part and an inter mediate plunger partconnecting said main part and said socketing punch, said internalshoulder being spaced from the opposite end of said inner sleeve adistance less than the length of said intermediate part whereby saidintermediate part, when resting against said internal shoulder, projectsbeyond said inner sleeve for actuation by said plunger main part.

8. Apparatus as described in claim 3 further including means forapplying fluid pressure to the inner end of said punch for driving thesame outwardly through said chuck and die means.

References Cited UNITED STATES PATENTS LEONIDAS VLACHOS, PrimmyExaminer.

